nathanmtom
commented
1 year ago @Doudou-Li Thank you for submitting your issue and I will do my best to try and help you.
I believe there are several asks/questions in this issue request, but I'll start with trying to resolve why you cannot implement a jammed hinge in the existing model.
- In response to the 'Index exceeds the number of array elements (1)' you need to be careful and that the joints used in the WECCCOMP_Fault_Implementation are actually PTOs and not constraints as used in WECCCOMP_Nonlinear_Model_Predictive. Therefore, in the
wecSimInputFile.myou are incorrectly defining constraints when they should be ptos. I suggest comparing thewecSimInputFile.mbetween these two cases to see how you need to update the input file when moving over the joints from the WECCCOMP_Fault_Implementation. Please explore these suggestions as it should then alleviate the issues with the algebraic loop you mentioned. - Your second question appears to be related to how you can run Monte-Carlo (or batch runs) using WEC-Sim. You are able to use our multiple conditions run (MRC) feature to automatically run cases one after the other, but understand the time step may be to small. However, the time step was small because of the filter used to estimate velocity from the measured displacement. If you do not need to use that as input to the controller you can potentially speed up the simulation.
Please follow-up if you are able to resolve your issue or have further questions.
Cheers, Nathan
Doudou-Li
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Is your feature request related to a problem? Please describe.
Yes, I am trying to add Jammed hinge into the Numerical model (WECCCOMP_Nonlinear_Model_Predictive). About the description of Jammed hinge, it can be found in a report ''Fault behavior of a wave energy converter: a benchmark model development'', written by Erica Michelle Lindbeck, Office of Science, Science Undergraduate Laboratory Internship Program.
First, I started to copy three constraints A, B and C from the WECCCOMP Fault implementation and pasted them into Numerical model (WECCCOMP_Nonlinear_Model_Predictive).
However, I got a problem when I run the WEC-Sim simulation as below:
Then I tried to replace the old simulink blocks 'Rotational PTO Actuation Torque' to the new version blocks in the three constraints.
When I run the simulation again, there had some new errors as following:
**Block diagram 'WaveStar_NMPC' contains 1 algebraic loop(s). To see more details about the loops use the command Simulink.BlockDiagram.getAlgebraicLoops('WaveStar_NMPC') or the command line Simulink debugger by typing sldebug('WaveStar_NMPC') in the MATLAB command window. To eliminate this message, set Algebraic loop to "none". Component: Simulink | Category: Block diagram warning Found algebraic loop containing: WaveStar_NMPC/C_Revolute1/Rotational PTO Actuation Torque/Assignment2 (algebraic variable) WaveStar_NMPC/C_Revolute1/MATLAB Function WaveStar_NMPC/Global Reference Frame/Solver Configuration/EVAL_KEY/INPUT_7_1_1 WaveStar_NMPC/B_Revolute/Rotational PTO Actuation Torque/Assignment2 WaveStar_NMPC/B_Revolute/MATLAB Function WaveStar_NMPC/Global Reference Frame/Solver Configuration/EVAL_KEY/INPUT_6_1_1 WaveStar_NMPC/A_Revolute/Rotational PTO Actuation Torque/Assignment2 WaveStar_NMPC/A_Revolute/MATLAB Function WaveStar_NMPC/Global Reference Frame/Solver Configuration/EVAL_KEY/INPUT_1_1_1 WaveStar_NMPC/Global Reference Frame/Solver Configuration/EVAL_KEY/OUTPUT_1_1 (algebraic variable) This algebraic loop may be resolved when the subsystem option 'Minimize algebraic loop occurrences' is selected on some or all of the atomic and enabled subsystems in this algebraic loop Component: Simulink | Category: Model Elapsed time is 9.043214 seconds.
Post-processing and saving... Duplicate data logging variable name, 'pto1_out' specified in both 'WaveStar_NMPC/Linear Motor/output' and 'WaveStar_NMPC/A_Revolute/Rotational PTO Actuation Torque/To Workspace' Component: Simulink | Category: Block error Error evaluating 'StopFcn' callback of Frames block (mask) 'WaveStar_NMPC/Global Reference Frame'. Callback string is 'run('stopWecSim')' Caused by: Unable to resolve the name clock_out.time.**
Could you please help me to solve the above problems?
Describe the solution you'd like
My aim is to do some tests for the robustness analysis of my designed MPC method. That is why I want to add some extra terms to bring some uncertainties or disturbances into the WEC-Sim numerical model.
What I expect is to analyse the MPC method clearly from its advantages and disadvantages.
I was thought to do some Monte-Carlo simulations in WEC-Sim. But I found this is also hard and may not possible to do.
Could you please help me to do robust analysis tests based on your WEC-Sim numerical model (WECCCOMP_Nonlinear_Model_Predictive)? I think I cannot do that analysis using WECCCOMP_Fault_Implementation cos the simulation step is too small and it is not suitable for MPC design.
Describe alternatives you've considered A clear and concise description of any alternative solutions or features you've considered.
Personal project context If this request is related to your project, please describe what you are attempting to do in your project so the WEC-Sim development team knows your end goal.
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